Various mobile hydraulically powered machines are known. Often such machines are self contained, engine powered, and hydraulically driven though a hydraulic pump and motor combination. As one example, a self-propelled sweeper 100 (FIG. 3) can be used to remove dust, dirt and debris from roads and streets around construction areas. In certain arrangements, one or more wheels of the machine are each driven by a corresponding hydraulic motor. Certain of such machines are towable to allow for transporting the machine from job site to job site without the need for loading and unloading the machine on a trailer. Such machines often come with individual mechanical disconnects allowing each wheel to rotate independently from its drive motor, for example to allow higher towing speeds.
A limitation of mechanical disconnect systems is that the drive system can be damaged if the machine is towed without the wheel being properly disengaged from the drive motor. If the machine is towed with one or more of the wheels engaged, the wheel rotation will move hydraulic fluid through the motor and will try to force the fluid through the hydraulic system, which can damage the hydraulic system. This condition can also create severe loading on the mechanical drive parts and tires of the machine.
Further, if one or more wheels is engaged while another wheel or wheels are disengaged, the wheel(s) and motor(s) that are still engaged can become a hydraulic pump forcing hydraulic fluid flow, via a hydraulic circuit, through the disengaged motor(s) and wheel(s). In certain situations, if left to rotate freely and with an ever-increasing flow of oil, both motors can exceed their design limits and fail, contaminating the entire hydraulic system.
Aspects of the present disclosure provide an alarm system to minimize these and other problems.